Enterprise applications are not only high-performance business engines driving efficiencies, but they are also flexible building blocks of business systems. A recent promising solution has risen in the form of services. A service, such as a web service, is a program representing a self-contained, self-describing piece of application functionality that can be found and accessed by other applications. A service is self-contained because the application using the service does not have to depend on anything other than the service itself, and self-describing because the description on how to use the service can be obtained from the service itself. The descriptions of the service are typically centrally stored and accessible through standard mechanisms, such as WSDL (Web Service Description Language).
Instead of requiring programmers to establish and maintain links between applications, services are loosely coupled, making connections simpler and more flexible and allowing application architects to more easily find and understand services offered by other cooperative applications. However, the problem that exists with services is that they are often designed to expose functionality of individual applications and thus are too limited to be efficient building blocks for enterprise-wide business processes. A solution to this shortfall has been the migration to a service oriented architecture (SOA). The SOA is an open architecture middleware, which builds on the benefits of services. The Enterprise Service Framework (ESF), which is commercially available from SAP AG, Walldorf, Germany, is an example of a SOA. The term “framework” refers to a structure of interrelated programs. The term “SOA” may also be used to refer to a distributed objects architecture, such as CORBA (Common Object Request Broker Architecture) and DCOM (Distributed Component Object Model).
The SOA enables the abstraction of business objects (BO), modeled as services (also referred to as enterprise services), from actual applications. Aggregating services into business-level enterprise services may provide more meaningful building blocks for the task of automating enterprise-scale business scenarios. The SOA also enables the use of a repository storing relevant pre-existing enterprise services, which can be made available to selected partners and customers. By using a repository, these selected partners and customers can use the pre-existing enterprise services to aid in the implementation of new services and corresponding business objects. The term business object (BO) represents an object, such as a data structure including data and operations, of significance to a business. Examples of business objects include a purchase order, a sales order, a flight reservation, a shipping order, customer information, employee information, and the like. A service may thus provide an interface to enable other services and applications to access and process (e.g., create, fill-in, save, query, delete, print, send, and the like) the business object. The proliferation of services and business objects as enterprise building blocks will continue, and, as such, software tools are required to facilitate their implementation.